Hey guys… What laser power will cut black and clear acrylic ( 6mm) quick and one pass…. And that will work with bb32?
A CO2 laser will cut both. Not sure on the power needed for one pass. My 40 watt C02 does it in about 4-5 passes, but I am cutting at a speed that is fast enough that the protective paper on the acrylic does not catch on fire. I plan to use my BB32 as the controller once I finish the modifications to it since there will be a rotary axis. If you are trying to do it with a diode, I do not think you will be able to. Diodes will not cut clear acrylic unless you paint it a dark color, but that is not ideal.
What am doing is numbers a letters….. so here is how it looks…. Clear will be sandwiched in between two blacks… my 5w laser will cut black … but lol but it will do it in 3 passes but on 10% speed with max laser… and it took 3 minutes to cut 10mm circle Tried clear… wont even budge lol its just melted it lol on the other hand…my cnc did cut both… but not happy with clamping.. and cant get it to cut nice and smooth maybe i cant figure out feeds and speeds? Or the bit? what would be a perfect bit to cut it?? Maybe i should start from there? Lol Was looking at 20w optical laser head… they did show it cuts 18mm black acrylic in one pass and it looked fast… but i dunno…
Wattage isnt the issue. Wavelength is. 405-445nm (blue diode) passes right through clear acrylic.10600um from a CO2 laser gets absorbed by acrylic. You need absorption to heat up the material to effect a cut. 445nm is great for engraving and light duty cutting on Organics, but not on Plastics
Transmittance curve for acrylic: (from Transmission Curves of Optics Materials - GS Plastic Optics) See how 400-450nm "transmissions" right through the material > 90% just lost going through the material and coming out the back. The tints in colored acrylics absorb "some" energy, but very little. Note at other wavelengths transmission drops to 0% (ie 100% absorbtion). Under infrared (10600um) clear acrylic is almost 100% opaque making CO2 lasers perfect for acrylic and explains their popularity in the signage world
Your laser sees the clear acrylic as a window and the light passes right through without melting anything. CO2 lasers being on a different wave length see the acrylic as a solid, non-transparent wall which in turn blocks the light beam causing heat to build up where the point of the beam strikes the surface thus causing melting.
If you want to cut clear acrylic. More specifically if you really want to cut anything. Diode lasers have their limitations. Great for burning images but cutting ability is limited.
I have a cheap k40 40 watt and it cuts acrylic very well. However, I do not believe it will do 6mm I. One pass unless you go real slow. It does make nice clean cuts though and clamping is not required. Being a cheap machine, they are finicky which is why I am upgrading mine with a grbl based controller (Black box 32) and making a larger cutting area. For cutting acrylic with the CNC router you need endmills designed for plastics like O-flutes.
Im willing to spend 2k for module only…. As i have a big enough machine… 4’x5’ Yes i did search the 0 flute endmills….. but laser much more cleaner and smoother…. Is there something i can attach to my cnc that will cut clear and black? Up to 2k$
Several examples in Laser Cutter Builds | OpenBuilds. Note these are high end builds and they can be extremely dangerous. OpenBuilds assumes no responsibility for posted designs. These designs are all posted by hobbyists. Have you tried flaming the edges of the spindle cut acrylic to smooth it out?
For what it is for , no it doesnt need to be that smooth…. And yes i did try flaming it just for fun and yes gets smoother…. What i meant smoother and cleaner is on cnc too much debris ( dont have a dust shoe ) and i havent cut it full depth so can see little step lines… but again… for what it will be you wont see any of it as it will be about 10’ above ground….
